package strings is
   type cercle is access string;
   type individu is access string;
   type message is access string;

   function "<"(C1,C2:cercle) return boolean;
   function "<"(C1,C2:individu) return boolean;

   function "<="(C1,C2:cercle) return boolean;
   function "<="(C1,C2:individu) return boolean;

   function ">"(C1,C2:cercle) return boolean;
   function ">"(C1,C2:individu) return boolean;

   function ">="(C1,C2:cercle) return boolean;
   function ">="(C1,C2:individu) return boolean;

   function "="(C1,C2:cercle) return boolean;
   function "="(C1,C2:individu) return boolean;


end strings;
